Authors : Afebu Kenneth Omokhagbo, Oladunjoye Micheal Adeyinka and Olayinka Abel Idowu
Abstract: The use of surface resistivity measurements in estimating aquifer hydraulic properties like hydraulic conductivity (K) and transmissivity (T) have been explored for various sedimentary environments with little emphasis on a basement complex environment. In an attempt to explore the applicability of this approach, surficial resistivity measurements involving Vertical Electrical Sounding (VES) using the Schlumberger electrode array were carried out at ten drilled and pump tested borehole points in a typical basement complex terrain of southwestern Nigeria comprising granite gneiss, quartzite/quartz schist and banded gneiss. Depth to basement as revealed by the processed VES data ranged between 3.8-25.5 m with a mean of 12.0 m. The pumping test result showed K-values to vary between 0.006-0.41 m day-1 (mean: 0.12 m day-1) while those from the geoelectric measurements varied between 0.0055-0.323 m day-1 (mean: 0.13 m day-1). t-values on the other hand varied between 0.4-17.0 m2 day-1 (mean: 5.3 m2 day-1) from the pumping test analysis and 0.044-4.7 m2 day-1 (mean: 1.5 m2 day-1) from surficial resistivity measurements. The correlation between the geophysically and hydro-geologically estimated hydraulic properties showed R = 0.78 for the K-values and R = 0.73 for the t-values. This to an extent shows the applicability of this approach in a basement complex area.
Afebu Kenneth Omokhagbo, Oladunjoye Micheal Adeyinka and Olayinka Abel Idowu, 2014. Applicability of Hydro-Geophysical Parameter Estimation in a Basement Complex Environment: Case Study of the University of Ibadan Campus, Southwestern Nigeria. Research Journal of Applied Sciences, 9: 27-36.